A new study indicates a biological Hail Mary employed to save Idaho’s critically imperiled sockeye salmon may have saved the species from extinction, and it shows promise the long-distance swimmers may one day recover.
Paul Kline, assistant chief of the Idaho Department of Fish and Game Fisheries Bureau, and Thomas Flagg, a supervisory fisheries biologist for the National Oceanic and Atmospheric Administration, published the study in Fisheries, a journal published by the American Fisheries Society.
The two scientists say data indicates the offspring of sockeye salmon that spawn naturally in Redfish Lake return from the ocean at a rate more than triple the return rate of sockeye raised in hatcheries.
That finding alone isn’t revolutionary. What makes it significant is that sockeye spawning in the wild and producing those better-returning fish are the product of hatcheries. They’re part of the state’s effort to use artificial production to not only stave off extinction but also seed Redfish Lake and other Sawtooth Valley lakes with spawners.
“This is a real American endangered species success story,” said Will Stelle, administrator of NOAA Fisheries’ West Coast Region. “With only a handful of remaining fish, biologists brought the best genetic science to bear and the region lent its lasting support. Now there is real potential that this species will be self-sustaining again. The sockeye didn’t give up hope and neither did we.”
Snake River sockeye salmon were listed as endangered in 1991 following several years of dismal returns. No sockeye returned to the basin in some years. In others, only a few adults made the 900-mile journey from the Pacific Ocean, up the Columbia, Snake and Salmon rivers. The most famous of what could have been the last of the species was Lonesome Larry, the single sockeye that returned to the basin in 1992.
In response, Idaho, the Shoshone-Bannock Tribes, federal fisheries officials and the Bonneville Power Administration began a captive breeding program — the equivalent of capturing wild animals, breeding them in zoos and then releasing the offspring into the wild.
For more than 20 years, Idaho and its partners have been doing just that. It started by capturing the few wild adult sockeye remaining and breeding them in hatcheries. They also captured wild smolts and raised them in hatcheries.
Some of the offspring of the initial captures were released to swim to the ocean, mature and eventually return. Others were held in hatcheries for their entire life cycles.
Over time, the program began producing and releasing more and more smolts, and allowed an increasing number of the returning adults to spawn in the wild.
When they compared the smolt-to-adult return rates of naturally produced fish versus those born in hatcheries, officials found the natural fish were more fit.
Scientific literature indicated bringing the fish into hatcheries would have some negative effects on the fitness of their offspring. Scientists theorized it would take many generations of fish spawning in the wild before such a difference would show up. Instead, the scientists documented it in just a few generations.
To be sure, sockeye remain in danger of going extinct and recovery is likely still a distant dream. But the results indicate it might not be as impossible as many had feared.
“We hoped we could get returns equivalent to what you’d expect to see from a hatchery,” said Flagg, manager of the NOAA Fisheries Northwest Fisheries’ Science Center’s Manchester Research Station. “We’ve seen the population respond even better than that, which bodes well for the idea that the lakes can produce the juveniles you’d want to see to get to recovery.”
That’s good news for the prospects of recovering the species and welcomed not only by scientists and anglers but also the people who directed money to the program.
“I think it’s one of the most successful projects the council has funded,” said Bill Booth, one of Idaho’s representatives on the Northwest Power and Conservation Council. “Really, Idaho Fish and Game deserves the credit for this. The work they have done over time has been from a sound scientific approach in the very beginning to really achieve a spectacular outcome.”
